Collections can be edited from:
the Music tab — for songs currently assigned to a Group
the Music Library — for all songs in the Subject
When collections are edited, those changes are reflected anywhere the collection is viewable.
Edit a collection assigned to a Group
Collections currently assigned to the Group can be edited from the Music tab.
Rename an existing collection
Tap the
Music tab
Tap the Collections tab at the top
Find the collection and tap the
options button
Tap Rename
Enter a name for the collection and then tap Save
Add or remove a song from an existing collection
Tap the
Music tab
Tap the Collections tab at the top
Tap the collection to open it
To add a song: Tap
add, select songs, then tap Add
To remove a song: Tapand tap Remove from Collection
Edit a collection in the Music Library
All collections in the Subject can be edited in the Music Library.
Navigate to the Music Library
Tap
Settings
Find and tap
Music Library
Tap the Collections tab at the top
Rename an existing collection
Find the collection and tap the
options button
Tap Rename
Enter a name for the collection and then tap Save
Add or remove a song from an existing collection
Tap the collection to open it
To add a song: Tap
add, select songs, then tap Add
To remove a song: Tapand tap Remove from Collection

Music tab
options button
add, select songs, then tap 
Settings
Music Library